Gaps in equality law are leading to “undesirable and unnecessary religious discrimination” in schools and the workplace and fuelling segregation, a report claims.

Discrimination against the non-religious and members of religious minorities remains lawful across much of public life in Britain a decade on from the Equality Act, the National Secular Society (NSS) said.

Campaigners say those who are already marginalised are most likely to be negatively affected by omissions in the 2010 act, and are calling for urgent reform relating to education, caste-based discrimination, and employment.

This includes the removal of the collective worship requirement for all state schools, and ending discrimination in admissions and recruitment or by having a curriculum that favours a certain religion.

Former equalities minister Baroness Lynne Featherstone wrote in a foreword to the report, Faith-shaped holes: how religious privilege is undermining equality law: “Until exemptions that create religious privilege are tackled and ended, we cannot claim to have created a just and fair society. We are all too aware that these are not abstract concepts and theoretical debates.

“As the UK becomes increasingly diverse, getting this right is vital for community cohesion; for democratic participation and legitimacy; and for ensuring all individuals are afforded the same opportunities and have the same chance in life.”

The NSS said the diversity of religion in the UK has increased, while more than 50% of British adults say they have no religion.

It said “exceptions to accommodate faith schools, faith-based admissions and religious practice in schools are leading to a level of religious discrimination that would not be tolerated in any other area of society”.

My daughter has no school to go to in her borough due to draconian and discriminatory criteria used by faith schools

It recommends that the Government removes exceptions that enable state-funded schools to discriminate against individuals on the basis of religion or belief.

The report says: “It would mean no state-funded school could discriminate against pupils in their admissions on the basis of their family’s religion or religious activities, or by having a curriculum that favours a particular religion or belief.

“It would also protect staff and governors from religion-based discrimination, and necessitate the removal of the collective worship requirement for all schools.

“Finally, it would end the privileging of religious families in the school transport policies of local authorities.”

Parents quoted in the report said their children have been ”locked out” of local schools, while others have been allocated faith schools against their wishes.

One parent said: “My daughter has no school to go to in her borough due to draconian and discriminatory criteria used by faith schools.”

Another said: “Parents are going to church just to get their children into a certain school, and I know for a fact they are atheists. It’s a farce.”

Instead, a system of secular community schools “would by its nature treat families of all religion and belief backgrounds equally”, the NSS said.

It also notes that caste-based discrimination and harassment have “become a feature of British life” due to Asian immigration.

It said up to hundreds of thousands of people are “without any meaningful protection against a particularly cruel form of discrimination” and is calling for “caste” to be included as a protected characteristic under the act.

The report also suggests that an exception in the act which allows employers to discriminate on the basis of religion or belief when there is a “genuine occupational requirement” is “being overused”.

It cited examples of job advertisements seeking candidates from particular religions where there was no clear explanation why such a person was required.

There needs to be greater clarification of what counts as a “genuine occupational requirement”, and greater enforcement if the law is breached, it said.

A Government Equality Hub spokeswoman said: “There is no place for discrimination in the UK. We are a nation that supports equality and diversity in all forms, and the Equality Act strives to foster equality across religions and secular interests.”